The present invention relates to biomolecules, and more specifically, to determining isoelectric points of biomolecules using capacitive sensors.
The isoelectric point of biomolecules is defined as the pH at which the net charge on the biomolecule is zero. It is a main property of proteins which plays an important role in purification and solubility. The isoelectric point is also used as an identification marker for proteins. FIG. 1 illustrates a typical method and setup for determining the isoelectric point is based on electrophoresis. In FIG. 1, the typical apparatus requires high voltages (>50V), is time consuming (˜2 to 16 hours), and is therefore expensive. The typical apparatus is approximately 1 square foot for measuring the isoelectric point.